--- /dev/null
+++ Libc/Libc-1725.40.4/tests/getenv.c
@@ -0,0 +1,162 @@
+#include <stdlib.h>
+
+#include <darwintest.h>
+#include <libc_private.h>
+
+T_DECL(setenv_getenv, "getenv returns value set by setenv")
+{
+	char *name = "foo";
+	char *value = "bar";
+	int setenv_rc = setenv(name, value, 0);
+	T_EXPECT_EQ(0, setenv_rc, "setenv must succeed with 0 return code");
+	char *getenv_result = getenv(name);
+	T_EXPECT_EQ_STR(value, getenv_result, "getenv must return setenv argument");
+}
+
+T_DECL(setenv_overwrite, "getenv returns the latest setenv argument")
+{
+	char *name = "foo";
+	char *first_value = "bar";
+	char *second_value = "baz";
+	int setenv_rc = 0;
+	setenv_rc = setenv(name, first_value, 0);
+	T_EXPECT_EQ(0, setenv_rc, "setenv must succeed with 0 return code");
+	setenv_rc = setenv(name, second_value, 1);
+	T_EXPECT_EQ(0, setenv_rc, "setenv must succeed with 0 return code");
+	char *getenv_result = getenv(name);
+	T_EXPECT_EQ_STR(second_value, getenv_result, "getenv must return the latest setenv argument");
+}
+
+T_DECL(setenv_dont_overwrite, "setenv respects overwrite")
+{
+	char *name = "foo";
+	char *first_value = "bar";
+	char *second_value = "baz";
+	int setenv_rc = 0;
+	setenv_rc = setenv(name, first_value, 0);
+	T_EXPECT_EQ(0, setenv_rc, "setenv must succeed with 0 return code");
+	setenv_rc = setenv(name, second_value, 0);
+	T_EXPECT_EQ(0, setenv_rc, "setenv must succeed with 0 return code");
+	char *getenv_result = getenv(name);
+	T_EXPECT_EQ_STR(first_value, getenv_result, "the second setenv must not overwrite the first one");
+}
+
+/* There are tests for leading '=' in values because BSDs used to strip them off: rdar://problem/19342460 */
+
+T_DECL(setenv_accepts_leading_eq_sign, "setenv accepts values starting with '='")
+{
+	char *name = "foo";
+	char *value = "=bar";
+	int setenv_rc = setenv(name, value, 0);
+	T_EXPECT_EQ(0, setenv_rc, "setenv must succeed with 0 return code");
+	char *getenv_result = getenv(name);
+	T_EXPECT_EQ_STR(value, getenv_result, "getenv must return setenv argument");
+}
+
+T_DECL(setenv_accepts_leading_eq_sign_overwrite, "setenv accepts values starting with '=' when overwriting an existing value")
+{
+	char *name = "foo";
+	char *first_value = "bar";
+	char *second_value = "=baz";
+	int setenv_rc = 0;
+	setenv_rc = setenv(name, first_value, 0);
+	T_EXPECT_EQ(0, setenv_rc, "setenv must succeed with 0 return code");
+	setenv_rc = setenv(name, second_value, 1);
+	T_EXPECT_EQ(0, setenv_rc, "setenv must succeed with 0 return code");
+	char *getenv_result = getenv(name);
+	T_EXPECT_EQ_STR(second_value, getenv_result, "getenv must return the latest setenv argument");
+}
+
+#pragma mark getenv_copy_np tests
+
+T_DECL(getenv_copy_np_returns_null, "getenv_copy_np returns NULL for non-existant variable")
+{
+	char *name = "alskfjapoeifhapoeifnaslkedfhjalsdkjfalsdkjf";
+	int unsetenv_rc = unsetenv(name);
+	T_EXPECT_EQ(0, unsetenv_rc, "unsetenv must succeed with 0 return code");
+	errno = 0;
+	char * getenv_copy_np_result = getenv_copy_np(name);
+	int save_errno = errno;
+	T_EXPECT_NULL(getenv_copy_np_result, "getenv_copy_np reurns NULL for unset environment variable");
+	T_EXPECT_EQ(0, save_errno, "getenv_copy_np must succeed without setting errno");
+}
+
+T_DECL(getenv_copy_np_empty, "getenv_copy_np returns empty string")
+{
+	char *name = "foo";
+	char *value = "";
+	int setenv_rc = setenv(name, value, 0);
+	T_EXPECT_EQ(0, setenv_rc, "setenv must succeed with 0 return code");
+	char * getenv_copy_np_result = getenv_copy_np(name);
+	T_EXPECT_EQ_STR(value, getenv_copy_np_result, "getenv_copy_np must return setenv argument");
+	free(getenv_copy_np_result);
+}
+
+T_DECL(setenv_getenv_copy_np, "getenv_copy_np returns value set by setenv")
+{
+	char *name = "foo";
+	char *value = "bar";
+	int setenv_rc = setenv(name, value, 0);
+	T_EXPECT_EQ(0, setenv_rc, "setenv must succeed with 0 return code");
+	char * getenv_copy_np_result = getenv_copy_np(name);
+	T_EXPECT_EQ_STR(value, getenv_copy_np_result, "getenv_copy_np must return setenv argument");
+	free(getenv_copy_np_result);
+}
+
+T_DECL(setenv_overwrite_getenv_copy_np, "getenv_copy_np returns the latest setenv argument")
+{
+	char *name = "foo";
+	char *first_value = "bar";
+	char *second_value = "baz";
+	int setenv_rc = 0;
+	setenv_rc = setenv(name, first_value, 0);
+	T_EXPECT_EQ(0, setenv_rc, "setenv must succeed with 0 return code");
+	setenv_rc = setenv(name, second_value, 1);
+	T_EXPECT_EQ(0, setenv_rc, "setenv must succeed with 0 return code");
+	char * getenv_copy_np_result = getenv_copy_np(name);
+	T_EXPECT_EQ_STR(second_value, getenv_copy_np_result, "getenv_copy_np must return the latest setenv argument");
+	free(getenv_copy_np_result);
+}
+
+T_DECL(setenv_dont_overwrite_getenv_copy_np, "setenv respects overwrite")
+{
+	char *name = "foo";
+	char *first_value = "bar";
+	char *second_value = "baz";
+	int setenv_rc = 0;
+	setenv_rc = setenv(name, first_value, 0);
+	T_EXPECT_EQ(0, setenv_rc, "setenv must succeed with 0 return code");
+	setenv_rc = setenv(name, second_value, 0);
+	T_EXPECT_EQ(0, setenv_rc, "setenv must succeed with 0 return code");
+	char * getenv_copy_np_result = getenv_copy_np(name);
+	T_EXPECT_EQ_STR(first_value, getenv_copy_np_result, "the second setenv must not overwrite the first one");
+	free(getenv_copy_np_result);
+}
+
+/* There are tests for leading '=' in values because BSDs used to strip them off: rdar://problem/19342460 */
+
+T_DECL(setenv_accepts_leading_eq_sign_getenv_copy_np, "setenv accepts values starting with '='")
+{
+	char *name = "foo";
+	char *value = "=bar";
+	int setenv_rc = setenv(name, value, 0);
+	T_EXPECT_EQ(0, setenv_rc, "setenv must succeed with 0 return code");
+	char * getenv_copy_np_result = getenv_copy_np(name);
+	T_EXPECT_EQ_STR(value, getenv_copy_np_result, "getenv_copy_np must return setenv argument");
+	free(getenv_copy_np_result);
+}
+
+T_DECL(setenv_accepts_leading_eq_sign_overwrite_getenv_copy_np, "setenv accepts values starting with '=' when overwriting an existing value")
+{
+	char *name = "foo";
+	char *first_value = "bar";
+	char *second_value = "=baz";
+	int setenv_rc = 0;
+	setenv_rc = setenv(name, first_value, 0);
+	T_EXPECT_EQ(0, setenv_rc, "setenv must succeed with 0 return code");
+	setenv_rc = setenv(name, second_value, 1);
+	T_EXPECT_EQ(0, setenv_rc, "setenv must succeed with 0 return code");
+	char * getenv_copy_np_result = getenv_copy_np(name);
+	T_EXPECT_EQ_STR(second_value, getenv_copy_np_result, "getenv_copy_np must return the latest setenv argument");
+	free(getenv_copy_np_result);
+}